My senior year of high school my father volunteered to do announcing at track meets.
Most people that did it (usually a member of the track team) would just make general announcements on the progress of the meet, e.g., "Zenith has 65 points, Anytown East has 51", or "All throwers report to the check-in area to have your implements weighed". My father in addition to standard announcements, started calling all the races and field events like a television announcer.
If the race was at all close he would get really excited and start yelling over the microphone, things like "Oh my God! Oh my God! It's Smith and Jones rounding the turn into the home straightaway, it's gonna be a barn-burner! They're neck and neck down the home straightaway, Smith pulling ahead, and he wins it by a hair in 5:02!!!" He would call these low-key dual meets like it was the Kentucky derby or something.
Also, my team had a number of nick-names for area runners, which he would use over the mic.